Percussion tools

ABSTRACT

A percussion tool employed in rock drilling and the like including a lower body portion, an upper body portion, a connecting mandrel extending from the upper body portion with the upper body portion comprised of a cylindrical portion, a hollow tubular body containing a column therein and a shaft connecting the upper body portion with a lower body portion which is comprised of a hollow body with a helical spring means contained therein and a bit attached to the lower end of the lower body portion.

O United States Patent 11 1 1111 3,842,920 Barnetche-Gonzalez 1 Oct. 22, 1974 1 PERCUSSION TOOLS 1.717.972 6/1929 Hartson .1 175/299 3,303,899 2 9 [761 Eduard" nametchficonlalez, 3.409.091 111192; 173/119 Culliacco 123, despachos 1307 and 1308' Mex'co l Mex'co Primary Examiner-James A. Leppink [22] Filed: Sept. 12, 1973 Attorney, Agent, or Firm-Armstrong, Nikaido &

W 211 App]. No.: 396,610 egner [57] ABSTRACT [30] Foreign Application Priority Data A percussion tool employed in rock drilling and the Feb. 19, 1973 Mexico 141655 like including a lower y P n pp y portion, a connecting mandrel extending from the [52] U.S. Cl. 175/299, 173/1 19 upper body portion with the upper body portion com- [51] Int. Cl. E2lb 1/06 prised of a cylindrical portion, a hollow tubular body [58] Field of Search 175/293, 299, 389; containing a column therein and a shaft connecting 173/119 the upper body portion with a lower body portion which is comprised of a hollow body with a helical [56] References Cited spring means contained therein and a bit attached to UNITED STATES PATENTS the lower end of the lower body portion. 1,372,257 3/1921 Swisher 175/389 4 Claims, 8 Drawing Figures 1 1 L33 1; l u 1 1 PAIENTED W239" SNEUIUF 3 SIIEHZOFS FIG. 5

FIG. 4

PATENIED 2 2 974 FIG. 6

SHiET 30F 3 PERCUSSION TOOLS BACKGROUND OF THE INVENTION This invention relates to percussion tools. More particularly, it relates to percussion tools employed in rock drilling and the like, and more specifically pertains to certain improvements provided on this class of tools.

Percussion tools are broadly known which by their own weight and due to gravity, provide a strong impact with a surface to be drilled. The purpose of this is to introduce into the surface a rupturing point or element and to allow the attack edges of a drilling bit to contact with said surface to be drilled, in order to effect said drilling. Recently, certain improvements in this class of tools have been introduced by forming said tool with a body comprised of an outer portion and an inner portion, carrying at the lower end thereof the rupturing means for breaking down the bottom of the formation being drilled; with an elastic means being arranged in said inner portion, and which is capable of storing en-' ergy, and so located as to be compressed when said outer portion of the tool is moved upwardly when said tool is hoisted preparatory to drilling, thus producing increased speed in said rupturing effect and said tool during its downward stroke.

Although this type of tool has been satisfactory, it has a disadvantage due to the fact that its outer portion is made as a sole piece and the mass thereof is distributed all along the longitudinal portion thereof. Therefore, the outer mass to inner mass ratio cannot be varied. Furthermore, bearing means are required to be provided in order to avoid inner body rotation and also a large top must be provided onto which said tool should insite during its downward stroke in order to strike the rupturing device. All these elements are substantially the same for every application thereof except for the rupturing device which can be changed. All this results in that, when loose soil is encountered, said tool becomes jammed since the weight thereof cannot be modified even if said rupturing device has been changed.

This invention has as its general object to obviate all of the above drawbacks upon providing certain im provements that allow greater efficiency and versatility for said tool.

It is a particular object of this invention to provide an improved percussion tool, wherein the lower large top as well as the bearing means have been eliminated to avoid the torsional revolving of the inner body.

Another object of this invention is to provide a tool as pointed out, wherein the weight thereof is concentrated on the lower portion of the same.

Another and further object of this invention is to provide a tool as pointed out, capable of being wholly disassembled or interchangeable as to the parts thereof, in order to increase or decrease the sizes, weights, drilling diameters, etc. of said tool, thus being suitable I01 any kind of soil or rock contemplated to be drilled.

It is still a further object of this invention to provide a tool as above specified, capable of providing a greater number of strokes per given time increment, together with greater hoisting capacity, greater power and, therefore, greater efficiency.

SUMMARY OF THE INVENTION In accordance with the present invention, a device in in the form of a percussion tool for rock drilling and the like is provided which is comprised generally of an upper body portion connected to a lower body portion and also connected to a mandrel extending from the upper body portion and where the upper body portion is comprised of a cylindrical portion, a hollow tubular body containing a column therein and a shaft connecting the upper body portion with the lower body portion which is comprised of a hollow body also and which contains a helical spring abutting against a threaded connection between the upper and lower body portions and a bit extending from the extreme lower area of said lower body portion and comprised of a rupturing means and a cutting edge.

BRIEF DESCRIPTION OF THE DRAWINGS Other further objects and advantages of this invention will be obvious in part and partially become apparent during the following disclosure of a preferred em bodiment of this invention, wherein reference is made to the accompanying drawings, wherein:

FIG. 1 is a plan view, partially schematical and partially sectional, illustrating a tool of the type employed in the present invention, inserted within a wellbore or the like;

FIG. 2 is a partially cut away longitudinal sectional view, showing the inner components of the upper portion of said tool, in a first condition therefor;

FIG. 3 is a view similar to FIG. 2, but showing the inner components of the lower portion of said tool, in a first condition;

FIG. 4 is a view similar to FIG. 2, but showing the inner components of the upper portion of said tool, in a second condition thereof;

FIG. 5 is a view similar to FIG. 3, but showing the inner components of the lower portion of said tool, in a second condition;

FIG. 6 is an upper plan view of the cutting or rupturing element or device employed as part of and in this invention;

FIG. 7 is an elevational view of the same; and

FIG. 8 is a lower plan view thereof.

DETAILED DESCRIPTION OF THE DRAWINGS Referring first to FIG. 1, there is shown therein a tool 10 of this invention, illustrated from the exterior thereof and wherein the numeral 20 corresponds to a lower portion or body. Numeral 30 shows a column or upper body; numeral 40 a connecting mandrel, and numeral S0 identifies a drilling cable, also referred to as a suspension line. Numeral 60 designates a wellbore within which said tool 10 is working; and numeral identifies generally a bit or rupturing portion.

As is common with this type of tool, said tool 10 is connected, through said line 50, by means of a con necting mandrel 40, thus providing a strong and hard mechanical connection so that said tool 10 can be hoisted from a drilling machine (not shown) up to a predetermined height in order to take advantage of gravity by dropping said tool from the altitude reached, so as to have impact with the bottom of the wellbore by means of the rupturing portion, knocked through an inner-shaft, as will be described hereinbelow. Thus, said rupturing portion will penetrate the bottom of the wellbore enough to form a rupture and allow for the attack edges or cutting edges of said bit 70 to remain in a position for cutting and bitting at said surface, in order to deepen said wellbore. This hoisting and dropping operation of the tool is effected repetitively, as is obvious in the art.

Referring now to FIGS. 2 and 3, which are complementary to each other, said tool 10, at the portions im proved by this invention comprises a lower rupturing portion or body, generally designed by numeral 70, and an upper body or column portion, generally designed by numeral 30. This upper portion 30 is formed by a top column portion 31, the top end of which is threaded connectively to a hoisting sleeve also referred to as a connecting mandrel, through a threaded piece 32. At the lower hollow end, said piece 31 is also connected threadedly by means of inner threads 33, with outer threads carried by a cylindrical body portion 34, enlarging the lower hollow region, and the lower end of which is solidly connected to a hollow tubular body 35, inside which there is the inner column portion 36, capable of being moved within said hollow region until being contacted by said body end 31, as a stop.

At the lower end, the inner column portion becomes solid and is provided with an inner threaded hole, wherein the upper threaded end 37 of a shaft 38 is received threadedly with said shaft extending along said tool from this point into the end wherein a bit 70 is to be inserted. Said shaft 38 is housed inside the hollow tubular body 35, extending substantially until it reaches the connection of the column or upper body portion 30 and the lower body portion 20. This connection is effected by means of a solid body 29, solidly connected to the lower end of said hollow body 35 and located so that its upper edge cooperates with the lower edge of said column 36 in order to maintain therebetween and about the corresponding shaft portion, a helical spring or any other energy elastomeric storing means, designed by numeral 39. As can be seen, all of the above elements constituting the tool have relatively small weight, with most of them being hollow, and those which are solid being of light weight due to its scarce volume. Thus, all the weight necessary to compress said spring 39 during the hoisting has been concentrated at said lower body 20, comprising a solid body 27, threadedly connected at 28 to said body 29, so that said portion 27 can be interchangeable to give greater or lesser weight to said tool, as well as vary its length and diameter.

Both body 29 and body 27 are provided with an axially central passage to provide for the free passage of said shaft 38, but preventing the displacement of said helical spring; therefore, said shaft can be introduced through said passage, but the spring will be compressed during the hoisting of the tool. The shaft has at the lower end thereofa threaded hole 24, wherein the rupturing means itself is connected; said rupturing means being designed by numeral 23, and provided at the free end thereof with a point of durability and shape charateristics adapted to effect the rupturing of said soil or other material. This point is designated by numeral 22. On its side, body 27 is threadedly connected at the lower end by threads 26 to the bit portion 70, formed with an inner gasket 21, for preventing the entrance of dirt and drilling materials into said tool. Said gasket surrounds the upper end of said rupturing means 23.

Therefore, with the above recited arrangement, substantially any portion or part of the tool can be interchanged, thanks to the threaded connection characteristics of most of the components thereof; and this can be obtained in an easy and quick way, to equate said tool to a given necessity.

Referring now to FIGS. 4 and 5, which are similar to FIGS. 2 and 3 above, there is shown therein the same tool, but with the position of the constituent elements drawn during the hoisting of said tool. Thus, it can be seen that, since all the outer portion is being directly hoisted, said inner column 36, together with said shaft 38 connected thereto and, therefore, said rupturing device 23 at the lower end thereof, will remain at the bottom of the hole, thus compressing said spring 39, and leaving the upper end of said column 36 with a hollow space 35' formed between the upper edge 36' of said column 36 and the lower edge 3] of said body 31. When the spring compression is effected, energy is stored so as when said hoisting ceases, and the dropping of the tool is started, it is to be added to the gravity force, the energy stored at said spring, thus increasing the descent speed and resulting in more strokes per time unity, greater strength in each stroke and greater efficiency of said tool. It is to be pointed out that each incidence is effected on the upper end 36' to be transmitted therefrom to said rupturing device 23 by means of said shaft 38; whereby the bit portion need not be shaped to receive said strokes.

Referring now to FIGS. 6 through 8, said bit is formed by four cross-shaped arms 71,72,73 and 74, each of them carrying a substantially circular portion inscribed at the junction of said arms and carrying at the center thereof an upward projection 77, provided with outer threads 78 to be coupled to threads 26 (FIGS. 3 and 5). At the center of said body 77 there is a circular passage 79, suitable for receiving the rupturing means 23. Each arm is formed with a downward slope 76, a side edge 72 and a lower edge or cutting edge 80. Said edge 80 is formed by the V-shaped cut at the lower end of each arm, as clearly appears from FIG. 8.

Thus, it will be obvious that when the tool falls, the rupturing device 22 at the same time breaks down and the edges 80 of said rupturing device bit the soil, or other material, upon impact of piece 31 to the upper portion of column 36.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed is:

1. A percussion tool suitable for drilling a geological formation, and comprising a means for hoisting said tool; a tool body; a bit means at the lower end of said body; means for rotating said bit attached thereto; a rupturing device carried by said tool at the lower end thereof; and an energy storing means, carried interiorly of said tool;

characterized in that said tool body is formed by a solid upper column, separatedly connected to a hollow intermediate column, within which said energy storing means is located;

a shaft means axially movable inside said hollow column;

said intermediate column being separatedly connected to a lower heavy body, connected in turn in a removable manner to said bit portion;

whereby all the components of said tool body are adapted to be changed in order to equate the weight and length of said tool to the specific needs of its application;

said shaft means being separatedly connected to said rupturing device to transfer thereto the energy stored in said energy storing device, as well as the strength imparted by said body when knocking on the upper end of said shaft.

2. A percussion tool according to claim 1, further vice are individually changeable.

t t is 

1. A percussion tool suitable for drilling a geological formation, and comprising a means for hoisting said tool; a tool body; a bit means at the lower end of said body; means for rotating said bit attached thereto; a rupturing device carried by said tool at the lower end thereof; and an energy storing means, carried interiorly of said tool; characterized in that said tool body is formed by a solid upper column, separatedly connected to a hollow intermediate column, within which said energy storing means is located; a shaft means axially movable inside said hollow column; said intermediate column being separatedly connected to a lower heavy body, connected in turn in a removable manner to said bit portion; whereby all the components of said tool body are adapted to be changed in order to equate the weight and length of said tool to the specific needs of its application; said shaft means being separatedly connected to said rupturing device to transfer thereto the energy stored in said energy storing device, as well as the strength imparted by said body when knocking on the upper end of said shaft.
 2. A percussion tool according to claim 1, further characterized in that said solid upper column of the tool body is arranged to impact on the solid upper end of a shaft device with the power of the stroke being proportional to the weight of the inner heavy region of said body.
 3. A percussion tool according to claim 1, further characterized in that said energy storing means has an energy storing capacity equal to the heavy inner portion of the tool body.
 4. A percussion tool according to claim 1 further characterized in that said bit portion and rupturing device are individually changeable. 